en tous cas

Question

Are "en tout cas" and "en tous cas" both acceptable ways of spelling this to mean "in any case". This exercise only accepted the latter, but I thought the former was correct.

Accepted Answer

'En tout cas' is also correct - the dictionaries Larousse and Robert seem to suggest 'en tout cas' as the more standard form, but apart from the Académie dictionary, other references checked also list ' en tous (les) cas ' as accepted. As a dictation, without 'les' included, there is no audible indicator that specifically informs the spelling. 
Figaro covers both but states that 'en tous cas' is less current. And then there is also 'dans tous les cas' ! 
There is clearly a difference of opinion among native French speakers as well regarding differentiation between these expressions. 
Céline and Cécile have answered somewhat related questions previously remarking that one expression was better than another is a particular situation - both I have seen referred to 'dans tous les cas' being preferred. On one occasion it was for the translation of the English phrase 'in any case' and the other for translation of the English phrase 'either way'. 
Other native French speakers, some bilingual and some not, have told me that they do not 'make' (or maybe they cannot 'make') the difference between these expressions in French. 
In any case, I wouldn't sweat it either way !
https://www.lefigaro.fr/langue-francaise/expressions-francaises/2017/07/23/37003-20170723ARTFIG00002-en-tout-cas-ne-faites-plus-la-faute.php

Answer

Bonjour Paul,
Thank you to Maarten for researching this particular expression and its spelling! Therefore, both spellings are now accepted in the exercise.
I hope this is helpful.
Bonne journée !